1. Field of the Invention
The present invention relates to a jointing device for a corrugated flexible conduit.
2. Description of the Related Art
Corrugated flexible conduits are used in large quantities as protective conduits for electrical equipment in buildings etc., and there is a demand for a jointing device for connecting a corrugated flexible conduit that is simple in construction and easy to handle. Corrugated flexible conduits are generally classified into a helical ridge type having a helical corrugation ridge (or groove) and a transverse ridge type having transverse corrugation ridges (or grooves) extending parallel with each other. The latter type, i.e., the transverse ridge type, is more flexible and easier to use than the former type, and thus is used in a larger quantity.
Many of conventional jointing devices for a corrugated flexible conduit are so constructed that an end portion of the corrugated flexible conduit is fitted on a connector section of the jointing device and is clamped by means of screws or the like in order to prevent the conduit from being separated from the jointing device. Recently, however, an increasing number of quick-connect type jointing devices has come to be used in which a corrugated flexible conduit can be engaged with and locked in the jointing device by simply inserting an end portion of the conduit into a connector section of the jointing device.
This quick-connect type jointing device is still associated with tile following problems:
(1) Since the connector mechanism is formed by an undercut part of a molding for structural reasons of a mold used, the number of locking claws is limited to two, making it difficult to obtain a sufficient strength against withdrawal (tensile strength) and a conduit retaining force; PA1 (2) It is not easy to insert a corrugated flexible conduit into the jointing device; PA1 (3) In cases where a corrugated flexible conduit is erroneously connected or during maintenance work, the flexible conduit cannot be easily detached from the connector section (while the helical ridge type corrugated conduit can be detached from the jointing device by rotating the connector section like a nut, the transverse ridge type corrugated conduit cannot be detached from the connector section and the connected part of the conduit must be cut off, which may make the conduit useless because of shortened length); PA1 (4) Although the jointing device permits the corrugated flexible conduit to be detached therefrom, the connector section thereof must be disassembled when connecting a flexible conduit thereto, thus requiring labor; and PA1 (5) The mold for making the jointing device is complicated in structure and thus is costly.